3～6岁双生子体型遗传分析

Genetic somatotype of twins aged 3-6 years

目的分析3～6岁幼儿体型各因子的遗传度,探讨遗传与环境因素对其体型发育的影响。方法采用Heath-Carter体型法对72对3～6岁同性别双生子[同卵双生子(MZ)42对,异卵双生子(DZ)30对]的体型进行分析,用Holzinger公式估算体型各因子遗传度。结果二维空间的体型离散距离(SDD)和三维空间体型位置距离(SAD)显示,MZ的体型较DZ更为接近;体型各因子对间方差在2类双生子间均无明显差异,中因子和外因子的对内方差DZ均明显大于MZ、组内相关系数MZ均明显大于DZ;内、中、外3个因子的遗传度分别为0.38、0.67、0.73。结论遗传与环境因素对3～6岁幼儿体型发育均有一定影响,内因子主要受环境影响,中、外因子受遗传因素影响较大。

Objective To analyze the heritabilities of somatotype components and to examine the genetic and environmental influences on the somatotype among twins aged 3 to 6 years.Methods The components of somatotype were calculated by using Heath-Carter method in 72 twin pairs,including 42 monozygotic（MZ）and 30 like-sex dizygotic（DZ）twin pairs aged 3 to 6 years.Heritabilities of somatotype components were estimated by Holzinger formula.Results The results of somatotype dispersion distance（SDD） and somatotype attitudinal distance（SAD） showed that the somatotype of MZ was more similar than that of DZ.The interpair variance of somatotype components showed no significant difference between MZ and DZ.The intrapair variance of mesomorphic and ectomorphic components was greater in DZ than in MZ,but the correlation coefficient was greater in MZ than in DZ.The estimated heritabilities of endomorphic,mesomorphic,and ectomorphic components were 0.38,0.67,and 0.73,respectively.Conclusion There might be genetic and environmental influence effects on somatotype of children aged 3 to 6 years.The endomorphic component is mainly determined by environmental factors,but mesomorphic and ectomorphic components are mainly affected by genetic ones.